On a side note on this. I think Unity had their own fork of Kallithea with some changes that aren't in the official version ? Or those features are backported later from the Unity release
at RhodeCode we used to have a hosted Mercurial repositories service. Actually, it was a per-customer isolated instance that we hosted on digital ocean. We have all the logic and code still here, i wonder if we should bring that back to have people host their Mercurial repositories.
The multi-repository code review is an interesting concept. Here at RhodeCode we're actually working on such solution to implement. This is in first to solve our internal problem of release code-review spanning usually two projects at once.
This is a hard and complex problem. Especially how to make code-review not too messy if you target 5-8 repos at once.
In RhodeCode we have a similar concept that we call diff ranges. It's not available in pull-request view directly, however, users can see this on a source repo if they select a range from changelog view.
Hey! Sourcegrapher who works on the browser extension and other integrations here.
The road to complete integration in a product is a bit longer as it takes collaboration if the product isn't open source. This is what we'd like in every product we integrate with.
However, I just did quite a bit of refactoring to make it easier and more straight forward to add support for new code hosts to the browser extension.
If you want to add support, we'd gladly accept a PR!
Have you looked at RhodeCode ? It's very similar like Gitlab with free Community Edition version that is also open-sourced. It's dedicated for self-hosting.